Rearend slop

mitchntx · July 12, 2004

2K1 2500HD - 8.1 - Alli - 2WD - 2 piece DS

In trying to track down a bad drive line vibration, I put the rear of the truck on jackstands (suspension loaded).

I had a friend run the speed up to the point of where the vibration starts and nothing. I did notice the the tire seemed out of round some and am taking it back for another check on that.

However, I did notice a small amount of "play" when I grabbed the tire to check for a wheel bearing. I could hear it, feel it and see the movement. It might be 1/8" at the top of the wheel.

The passenger side did not have this "movement".

My Trans AM race car has all kinds of "end play". But it's a C-Clip rear end and expected.

Something else I noted and not sure about is the rubber isolator on the carrier bearing. Mine is awefully pliable and I can move it quite a bit. I also notice that there are "slits" in the rubber. Is this normal?

snoman · July 12, 2004

You can easily adjust wheel bearing in a full floated but I would check drive shaft balance first as GM does not have a good track record with this issue.

Chevyfreek · July 12, 2004

You could also try rotating the tires and see if you notice the vibration still. If you have a tire that is out of balance or out of round that would cause a vibration for sure. What kind of milage do you have on the truck? The U-joint in the driveshafts on these trucks are prone to faliure once they hit over 60,000mi. A couple of new U-joints and having the drive shaft balanced may be a good idea like snoman suggested. I am thinking about having this done on my truck in the next few months. I almost at 70,000mi on my 01' HD...

mitchntx · July 12, 2004

I'm at 40K and the tires are about 1K old.

I've had the truck back at the tire shop 3 times for balance issues and am assured the tires/balance are spot on ...

Scyry · July 12, 2004

If you think the tire is out of round, take the wheel off and roll it along a flat area of concrete. You should be able to see it. Last set of tires I bought I had one that could not be balanced by the tire shop I bought it from, 3 tries. I took it to my uncle's shop and when I was rolling it over to his balancer I noticed it wasn't round. I took it back to the tire shop and they got me a new tire. It is an easy check, and worth a try.

snoman · July 12, 2004

I had to have the drive shaft balance on my burb at my expensive when new to get a "rumble" out of it at certain speeds. As a rule, GM usually does a poor job balancing drive shafts on trucks.